Impress (5)
I believe the answer is:
stamp
'impress' is the definition.
(I know that impress is the is a more specific form of the action of stamp.)
This is all the clue.
(Other definitions for stamp that I've seen before include "Imprinted mark" , "Use a die; character" , "One has picture of Queen" , "Impress with a mark" , "squash?" .)